In the petrochemical catalysis field, acidic catalytic materials are used as the catalyst in most hydrocarbon conversion reactions, such as cracking reaction, alkylation, reforming reaction, stacking reaction, isomerization, disproportionation reaction and the like (HOU Xianglin, Oil Refining Technologies in China, China Petrochemical Press, 1991). Thus acidic catalytic materials play a very important role in the petrochemical catalysis field. Research and development of acidic catalytic materials having higher performances are the important tasks for scientific research works.
The acidity properties of the acidic catalytic materials primarily include acid sites density, acid strength, acid sites type (Brönsted acid or Lewis acid), and have a notable and important effect on the catalytic reaction in which the acidic catalytic materials are used as the catalyst (WU Yue, Catalysis Chemistry, Science Press, Beijing, 2000, pages 162-196; HAN Weiping, Introduction of Catalysis Chemistry, Science Press, Beijng, 2003, pages 172-238; HUANG Zhongtao, ZENG Zhaohuai, Catalysis During Petrochemical Process, China Petrochemical Press, Beijing, 1995, pages 209-253). The acid sites density of the acidic catalyst plays an essential role in the hydrocarbon conversion reactions, such as cracking reaction, alkylation reaction and the like, and it can greatly improve the reaction selectivity (HE Mingyuan, Green Chemistry Related to Petroleum Refining and Petrochemical Production, China Petrochemical Press, Beijing, 2005, pages 109-169). The acidic catalytic materials can be classified into two types, i.e. liquid acids such as sulfuric acid, hydrofluoric acid and the like, and solid acids such as molecular sieve, superacid, loading-type acid catalytic material, acidic ion resin and the like. Liquid acids have a very high acid sites density (calculated by mol H+/g), and all are Brönsted acid sites. Generally, the acid sites density of the solid acids is less than the acid sites density of the liquid acids by two orders of magnitude because of structural restriction. The acid sites density of almost all solid acid catalytic materials prepared according to the prior art cannot reach to the order of magnitude of the liquid acid. The acidity properties of the liquid acid and solid acid catalysts are listed in Table 1.
TABLE 1Acidity properties of the acid catalystAcid sitesdensity (molAcid strengthAcidAcid-catalytic materialsH+/g)(−Ho)sites typeSulfuric acid (100%)  20 × 10−311.99BHF (100%)  50 × 10−3—BUSY molecular sieve catalyst 0.4 × 10−3—B and L(Si/Al = 3)Superacid SO4−2/ZrO2 0.1 × 10−314.52B and LH3PW12O40/SiO2 (having a0.26 × 10−313.16Bloading capacity of 25%)highly acidic ion resin0.45 × 10−310.10B and LB: Brönsted acid;L: Lewis acid